Why Hypercars Don't Compete in IMSA?

Endurance racing has worked to unify the regulations of the Le Mans Hypercar (LMH) and Le Mans Daytona hybrid (LMDh) categories. This effort aims to attract more manufacturers and balance competition between the wec and the IMSA series. However, despite regulatory convergence, LMH hypercars have not participated in IMSA.

If you follow endurance racing, you may have wondered why, if the Porsche 963 and Cadillac V-Series.R competing in IMSA are going to race the 24 Hours of Le Mans, which is part of the WEC championship, the Ferrari 499P and Toyota GR010 do not race the 24 Hours of Daytona, which is the first round of the IMSA championship.

Regulation Convergence

The Automobile Club de l’Ouest (ACO) and the International Motor Sports Association (IMSA) worked together to create a regulatory framework that allows LMH and LMDh vehicles to participate in major endurance races. This effort included the development of the Balance of Performance (BoP) to balance the technical differences between both categories and ensure fair competition.

Technical Differences and Balance of Performance

Despite regulatory convergence, there are key differences between LMH and LMDh:

• LMH: Allow greater design freedom, including the optional use of hybrid systems on the front axle, providing all-wheel drive. This flexibility has attracted brands like Toyota, Peugeot, and Ferrari, who have developed their hypercars specifically for the WEC. LMH cars are homologated using the Sauber wind tunnel in Switzerland and would need to go through the Windshear wind tunnel in North Carolina to be approved to race in IMSA.
• LMDh: Based on LMP2 chassis with standardized hybrid systems on the rear axle, resulting in rear-wheel drive. This more economical approach facilitates the participation of private teams and has attracted manufacturers like Porsche, BMW, Cadillac, and Lamborghini, who compete in both IMSA and the WEC.

Homologation and Procedures

LMH cars must go through a homologation process in both Europe and the United States to compete in both series. This dual process is complex and expensive, discouraging hypercar participation in IMSA.

Economic Factors

The development and homologation of LMH cars are more expensive than LMDh. IMSA has adopted LMDh precisely because of their more economical approach, facilitating the participation of private teams. Implementing LMH in IMSA would involve high costs, which is not attractive for many teams.

Current Cars in IMSA

• Cadillac V-Series.R
• Porsche 963
• BMW M Hybrid V8
• Lamborghini SC63
• Acura ARX-06

It is worth noting that the Acura ARX-06 is the only one of these cars not competing in the WEC, even though it can be entered in both championships.

Current Cars in the WEC

• Toyota GR010 Hybrid
• Ferrari 499P
• Peugeot 9X8
• Isotta Fraschini Tipo 6-C

Aston Martin is expected to debut in 2025 with the Valkyrie.

Balance of Performance

The BoP is crucial to maintain fair competition between LMH and LMDh. The technical differences between both categories complicate the implementation of an effective BoP for LMH in IMSA, creating an additional challenge that has not been satisfactorily resolved.

Current Status and Future

Despite some manufacturers' interest in bringing LMH to IMSA, current technical and economic barriers make their participation unfeasible in the short term. Regulatory convergence has allowed LMDh to compete in both series, but LMH remains limited to the WEC until these challenges are resolved.